LIDAR imaging systems, which are capable of high-speed 3D imaging, are widely used in for example autonomous vehicles, 3D virtual reproduction systems, 3D printing and aerial photography. It is highly desired to articulately incorporate and spatially integrate all the critical components of a LIDAR imaging system including laser sources, illumination manipulation optics and detectors, into a highly precision, compact configuration for expanding such a powerful system to a broad range of applications.
The LIDAR system developed by Google (U.S. Pat. No. 8,836,922B1) is a typical system currently used for commercial autonomous vehicles. The operation principle of the system is shown in FIG. 1. The optical engine of the LIDAR system includes a plurality of light sources 222, which are configured to emit pulsed laser beams. The pulsed laser beams are driven to form beams 204 through a tiny exit aperture 226 and the beams 204 propagate in a transmit path that extends through a shared space 240 towards a lens 250. The lens 250 collimates the beams 204 to provide collimated light beams, then the collimated light beams transmit to and are reflected by an external object 900. After transmitting through the lens 250 again, the collimated light beams form focused beams 208 which transmit into the shared space 240 and are reflected by the wall 244 towards a plurality of detectors 232. The beams are then detected by the plurality of detectors 232 to obtain the pulse signal intensity and the time difference data relative to the pulsed laser beams to obtain the information about distances and orientations of the external object.
Though as an integrated LIDAR system of such, the LIDAR imaging device in the prior art disclosed in U.S. Pat. No. 8,836,922B1 is noticed with certain conflicting optical features as shown in FIG. 1. Among many of optical and systematic drawbacks, the wall 244 is “broken” or interrupted with an exit aperture 226 which causes direct interference to reflection of the focused light 208; however, the disclosed optical configuration mandates such exit aperture 226 for guiding the beams 204 through the shared space 240 to transmit through the device for illuminating an external object to image. Such drawbacks are inherited by the fundamental architect of such an optical and imaging system yet to be redesigned and integrated.